New research has found that urban Great Tits have lower levels of stress hormones than those in woodland habitats.
Certain species of animals, especially birds, adjust well to human-created environments. Great Tit is one of those species – and researchers at Lund University have found that those living in urban areas, close to humans, are less stressed than those in woodland habitats.
Urban Great Tits have lower levels of stress hormones than those in woodland habitats, a new study shows (Clive Daelman).
"Great Tit's high cognitive capacity means it is highly adaptable, and urban Great Tits seem to have adapted so well to the new environment that they are not stressed by high population density. Another possible explanation is that it was the most intelligent and most flexible individuals who succeeded in colonizing urban environments in the first place," says Anders Brodin, biologist at Lund University and lead author of the paper published in Conservation Physiology.
The most common stress hormone in birds is corticosterone. Researchers compared levels of this hormone in Great Tits from various urban environments, such as parks and private gardens, with their counterparts in woodland habitats. In this study, Brodin and his colleague Hannah Watson have instead measured levels in the birds' tail feathers.
"The tail feathers grow over two to three weeks in late summer and early autumn, so they provide a good measurement of the average hormone level over a continuous period. During this time, winter flocks form around feeding habits and a high rank is important in order to survive the winter. This leads to a lot of skirmishes as individuals attempt to establish themselves in the flock," said Watson.
Reference
Brodin, A, & Watson, H. 2023. Feather corticosterone reveals that urban great tits experience lower corticosterone exposure than forest individuals during dominance-rank establishment. Conservation Physiology. DOI: 10.1093/conphys/coad033
